This invention relates to programmable thermostats. Specifically, it relates to the method and means by which the operator of the thermostat programs the thermostat.
Programmable thermostats have been widely used since the invention of the microprocessor. Early programmable thermostat designs are illustrated in U.S. Pat. No. 4,314,665 issued to Michael R. Levine entitled "Electronic Thermostat" and U.S. Pat. No. 4,071,745 issued to B. C. Hall entitled "Programmable Time Varying Control System and Method." These patents illustrate the use of what is commonly known as "Time and Temperature Pairs." The use of time and temperature pairs allowed for programmable thermostats to be set to varying temperatures based on the time of day. Programmable thermostats are most commonly used to set the temperature to a desired temperature while the home or office was occupied and to a secondary temperature while the home or office was unoccupied. The second temperature would be at a lower or higher temperature than the desired temperature and was utilized to conserve energy. These programmable thermostats encompass the majority of the market with respect to electronic thermostats.
With the invention of the programmable thermostat, the users were required to program these thermostats. Many of these thermostats required the user to program numerous time and temperature pairs so that this thermostat could adjust to their schedules. Most thermostats of this category required four separate time and temperature pairs for each day of the week and a second time and temperature pair for the weekend. As an example, in a home located in the midwest, in the wintertime, a user may program the thermostat to warm the home to a temperature of 68.degree. Fahrenheit by 6:00 a.m. so that the home is warm when they rise from bed. The user will then program the thermostat to drop to 64.degree. at 8:00 a.m. so that the furnace does not heat an empty home. The user then sets the thermostat to return the temperature to 68.degree. at approximately 4:30 p.m. so that the home is at a comfortable temperature when the user returns. Finally, the user will set the temperature down to 66.degree. at 11:00 p.m. to conserve energy while the users are sleeping. These time and temperature pairs are often times grouped into five-day weekday patterns with a separate Saturday and a Sunday pattern, requiring the four time and temperature pairs to be programmed for the weekday settings and reprogrammed again for the weekend settings. On more sophisticated thermostats, a separate time and temperature pair for each of the four settings may be input for each day of the week. This programming requires that a large amount of information be presented to the user in a coherent manner.
Most thermostats currently use a single display in which the day-to-day status of the thermostat is displayed and the programming information is displayed. By using a single display, users are often confused as to whether they are programming the thermostat or the thermostat is running. Due to this confusion, users often incorrectly program their thermostats or have difficulty programming the thermostat. One of the more common errors made by users is due to the thermostat's software. For instance, after remaining idle for a period of time while in the programming mode, the thermostat will return to the run mode, which leaves many users believing they have completed the programming of the thermostat. Further, many of the programming functions look similar to the day-to-day functions of the thermostat, which may confuse the user. This is because the same area of the display is used to show the current time and the program time as well as the current temperature and the programmed set point. These areas of the display are the most prominent areas. Users will often not notice smaller auxiliary labels that differentiate between programming and normal operation. The object of this invention is to provide a thermostat which is both easy to program and easy to read.